Improvement in cqgipressio



M. ADLER.

-Chord for Bridge-Girders.

Improvement in Compressive P ateh'ied lune/25. 1872.

MICHAEL ADLER, or CANTON, euro.

IMPROVEMENT IN COMPRESSION-CHGRDS FOR BRIDGE-'GIRDERS.

Specification forming part of Letters Patent No. 125,350, dated June 25,1872.

SPECIFICATION.

v To all whom it may concern Be it known that I, IVIIOHAEL ADLER, ofCanton, in the county of Stark and State of Ohio, have invented certainnew and useful Improvements in Compressive Chord for Arched or TrussGirders; and that the following is a full, clear, and exactspecification thereof, which will enable others skilled in the art tomake and use the said'invention.

Most of the tubular compressive chords heretofore constructed forwrought-iron girders, excepting such as aremade wholly of channelbar orI beams and plates, are made of peculiar shaped iron, which requiresspecial rolls or machinery for its production, and which is notordinarily foundin market, of all the dif-. ferent sizes desirable forthe various spans of bridge-work which the builder is called upon toconstruct. My invention is designed to obviate this objection by givingto the builder a construction of the common angle L, T, I, andchannel-iron and flat plate, which can be readily obtained in market, ofany size required to adapt my construction to any ordinary span, andwhich will afford a strong and economical chord; and to this end itconsists in the combination of two L-angle or T-iron bars with a channelor I-bar, said L-angle or T-bars being riveted by one leg to the flangesof the channel or I -bar, and the said three parts being combined withor riveted to a plate or T- bar, or three similar bars, or three similarbars and a plate, so as to form a tubular chord of any ordinary sizerequired, as is hereinafter more fully shown.

In the accompanying drawing, sections A, 13,0, D, and E represent thevarious modified forms of my chord. Figure 1 is an end view of one-halfof a bow-string girder having an arch made in the form of section A.Figs. 2 and 3 are side view and enlarged end view of a bow-string girderhaving an arch made in the form of section B. Fig. 4. is a side view ofa portion of a truss-girder made with an upper chord in the form ofsection I). Fig. 5

is an end view of the upper chord shown in Fig. 4. Fig. 6 is an end viewof one-half of a bow-string girder having an arch made in the form ofsection E. Fig. 7 is a side view of a portion of the girder shown inFig. 6.

In section A are shown two L-irons, H H,

which are distinguished from angle-iron by having legs a of unequallengths, and which are united by rivets to the flanges b b of thechannel-bar G, as shown. To the flanges a a of these L-irons is rivetedthe'plate F; or, if preferred, in order to obtain greater cross-sectionand vertical stiffness, a T-bar, which differs mainly from a flat platein that it has the flange or rib a, indicated by dotted lines, may beused in the place of the plate F.

In section Bare shown the two L-irons H H, riveted to the channelbar G,as before described, and to the flanges of the legs a a of these irons HH are riveted the legs of two similar L-irons, H H, which are likewiseriveted to a channel-bar, G, thus giving a section of considerablygreater outside dimensions than that of section A. Where the form shownin section B is required in an arch or chord of moderate verticaldimensions, say six inches. the two T-bars H a H H a H may be used inplace of the four L-irons H H H H, as is shown in section G, thus savingtwo rows of rivets, as will be seen by comparing section 0 with sectionB. Where greater lateral stiffness is required in the'chord than isgiven in the sections just described, a flat plate, F, may be rivetedbetween the L-irons H H H H, thus forming a chord of the form shown bysection D. Where an increase in both the lateral and vertical stiffnessis required, the chord can be made in the form shown in section E, wherethe long legs of the L-irons H H are arranged in a horizontal position,and the channel-bars G G and plate F are placed in a vertical position,as shown.

In the practical application of these various sections to bridge-work,as shown by the examples given in drawing, Fig. l'shows the section A inthe form of an arch for a bowstring girder, where its ends rest on shoesW, and are connected by lower chords 0 0, which are supported by )(-ironrods P bolted between said chords, and run through the arch in anordinary manner.

In Figs. 2 and 3 the arch is'of the general form of section B, exceptthat the bars H H are of angle-iron instead of L-iron-i. e., the legs ofsaid bars are of the same length instead of being of unequal lengths.The man ner of combining this arch with the shoes W, lower chords 0 0,posts P P, and truss-rods 0 0, to form the bow-string girder, is toowell known to bridge-builders to require further description than thatgiven by the drawing.

The'upper chord of the truss-girder, shown 7 in Figs. 4 and 5, is of thegeneral form shown in section D, except that angle-irons are used inplace of the L-irons shown in section D. The posts K L M, link-chords N,and main and counter rods 0 d are combined with the upper chord in theordinary manner. The lateral compressive brace I I J J, formed byuniting four angle-bars back to back, in column form, by means of rivetsand intervening thimbles, is readily united to the upper chord byrunning the upper and lower angle-bars I I and J J of said brace overthe horizontal legs of the chord-bars H H", and securing them by rivets,as shown.

Section E is shown as the arch of a bowstring girder in Figs. 6 and 7,and as this section will usually be used in arches of large span, wherea heavy lower chord is required, it is represented in said figures asbeing used with three plate-chords, i 43 t, placed edgewise and abreast.The post f f h f f consists of four an gle-irons, f f f f, arranged twoabreast, and having their lower ends flattened out and bolted betweenthe chords i i 6. These an glebars are spread out above said lowerchords, and are united by intervening lattice-bars h riveted betweenthem, and the bolts n n are riveted between their upper ends, and passthrough the arch-bars H H, with jam-nuts above and below, in theordinary manner. The ears m m are riveted to the vertical legs of thelower arch-bars H H, and the eyes on the truss-rods g g are secured bybolts between said ears, the lower ends of said trussrods passingthrough an angle-block, x, placed below the chords 11 i 6. Where a stillgreater cross-section for the chord is required than is shown in thesections described, I-bcams may be used in place of the channel-bars Gand G, which will give the additional flange-section indicated by dottedlines U U in section E.

I am aware that chords have been before constructed of two flat platesand two or more channel or I beams, in which the plates are usuallyemployed as side pieces when said chord is used in arched bridges, and Ilay no claim to such construction.

What I claim herein as new and of my invention, and desire to secure byLetters Pat cut, is

1. The combination of two L or angle irons H H with a channel or I beam,G, the legs of said L or angle irons being riveted to the flanges ofsaid channel or I beam, and the said combination forming the basis ofcon struction for a compressive chord, substantially as is herein setforth.

2. The combination of the two L-irons H H, channel-bar G, and plate or Tbar F, as represented in section A, for the purpose specified.

3. The combination of the four L or angle irons H H H H and the twochannel or I beams G G, substantially in the manner and for the purposespecified.

4. The combination of the two T-bars H a H H a. H and the two channel orI beams G G, substantially as and for the purpose specified.

5. The combination of the plate F, four angle or L irons H H H H, andtwo channel or I beams G G, said parts being arranged and combinedsubstantially as and for the purpose specified.

As evidence of the foregoing, witness my hand this 11th day of December,A. D. 1871.

' MICHAEL ADLER.

Witnesses:

J 013 ABBOTT, ANDREW OHOFFIN.

